1. Build a device which will input a 4-bit two's complement number and output the square of the number. Use Binary Coded Decimal representation for the input. Fill out the truth table for the device and calculate the minimal sum logic for each output. 2. Use full adders to design a device which will calculate 8x-y, where x and y are 4-bit signed inputs. Use 8-bit arithmetic. 3. Write the truth table for a device which will input a 4-bit signed number and output the absolute value of twice the number. The output should be in Binary Coded Decimal representation. 4. Use Full Adders and logic gates to design a device which will multiply a given 4-bit signed input x by -2.